Apparatus for processing blankets



SePt- 29 1964 J. l.. VAN HuYzEN APPARATUS FOR PROCESSING BLANKETS Original Filed April 5, 1960 INVENTGRZ JACQUES L. VAN HUYZEN ATTYS.

United States Patent O 3,150,468 APPARATUS FUR PROCESSING BLANKETS Jacques L. van Huyzen, Altoona, Pa., assignor to Cherno- Vive Processes, Inc., Altoona, Pa., a corporation of Delaware Original application Apr. 5, 1960, Ser. No. 20,075, now Patent No. 3,075,247, dated Jan. 29, 1963. Divided and this application July 10, 1962, Ser. No. 208,786 2 Claims. (Cl. 5138) vthe image to the paper, cardboard or other material on which it is desired to print the image. The rubber blanket generally comprises a rubber layer with a smooth outer transfer surface and a cloth backing. For best results in transferring the image from the outer transfer surface of the blanket it is essential that this surface is kept smooth, and that the thickness of the blanket is substantially uniform throughout its length and width.

In some instances, however, the blankets develop low spots or depressions in the outer layer during the printing operation.

These depressions in some instances affect proper image transfer, and therefore the blanket is no longer ,suitable for use. The low spots or depressions may be caused, for example, by paper misfeeding or jamming which tends to depress the rubber surface of thevblanket,

by accumulation of dirt or other foreign matter which adheres to the smooth rubber surface, by chemicals in thevprinting ink which contact and etch the rubber surface, `and other factors. In the past it has not'been possible to process such blankets and it has been necessary to replace the blankets, thereby incurring considerable expense.

The present invention provides an apparatus embodying novel features which insure restoration of a blanket to a condition suitable |for re-use. According to the present invention, the rubber layer of the blanket is treated with a composition causing it to swell to more than twice its original thickness, and thereafter a predetermined amount Vof rubber is removed from the outer surface to provide a blanket of uniform thickness having a smooth rubber transfer surface.

The various features and details of the construction of the apparatus are more fully set forth and described with reference to the accompanying drawings, in which:

FIG. l is a perspective view of a blanket used in offset or lithographie processes;

FIG. 2 is an enlarged sectional View taken along line 2-2 of FIG. l, showing the components of the blanket;

FIG. 3 is a schematic side elevational view of a rolling mill for compressing and smoothing the blanket;

FIG. 4 is a schematic plan view of an abrasion apparatus made in accordance with the present invention for removing predetermined amount of the outer layer of the blanket, and

FIG. 5 is a sectional view taken along line 5 5 of FIG. 4, showing alternate positions of the abrasion roller.

Referring now to the drawings, FIGS. l and 2 show a type of blanket which is adapted to be processed by the t apparatus of the present invention. The blanket cornprises an outer layer 11 of resilient material, such as y rubber, anda cloth backing 12 which preferably is a tightly woven, smooth material. The blanket 10, as illus- ICC trated in FIG. 2, may comprise two layers of resilient material, wherein the intermediate layer 13 may be made of a harder, or less resilient, composition than the outer layer 11. The total thickness of the blanket is generally in the order of 0.06 inch, and the individual layers 11, 12 and 13 are approximately 0.02 inch thick.

The method of processing blankets consists generally of three operations; a preliminary smoothing operation, a swelling and reducing or abrasion operation, wherein the rubber is caused to swell and in which a predetermined amount of rubber is removed from the blanket, and a final compressing or smoothing operation.

The blanket 10 is prepared for the preliminary compressing and smoothing operation by first scrubbing the cloth backing 12 and the outer transfer surface of the layer 11 with a suitable detergent and water solution to remove grease, dirt, loose ink, and other foreign matter. The blanket is then rinsed and hung to dry. After the blanket is dried completely, a solution of cellulose may be applied to the cloth backing in order to lill in small imperfections, and also to even out the cloth. The cellulose solution is preferably one composed of approximately 2 parts methylcellulose and 98 parts water. The solution is prepared by stirring one ounce of methyl-cellulose in 20 iiuid ounces of boiling water. This solution, after standing for approximately 30minutes, is then mixed 1with about 60 duid ounces of cold water. v In this manner the cellulose will dissolve completely in the cold Water without lumps. An example of a methyl-cellulose having the desired characteristics, which is commercially available on the market is a methyl-cellulose supplied by the Dow Chemical Company.

The next step in the process of the present invention is preparing the blanket for the initial or preliminary smoothing, or compressing operation. To this end a first composition is applied to the cloth side of the blanket to permit the cloth to be evenly compressed and straightened out in the operation, and also to the rubber transfer surface of the blanket in order to soften the rubber slightly. This composition is preferably one consisting of 33 parts benzol, 16 parts chloroform, 5 parts carbon-tetrachloride, 3 parts emulsifying detergent, and 43 parts water. ,When the blanket is suiliciently dried, it is subjected to compression in order to smoothfout any projecting portions of the cloth surface, and also to smooth the rubber surface thereof.

Thereafter, a second composition is appliedto the rubber surface of the blanket causing it to swell. The blanket is then aged to permit the proper swelling action to take place, as a result of which the rubber layer is swollen to more than twice its original thickness in preparation for the abrasion operation. This composition preferably consists of 3l parts sulphurated hydrocarbondistillate, 28 parts benzol, 28 parts chloroform, 1 2 partsrammonia, and 1 part pine needle oil. In this condition the blanket is now ready for the reducing or abrasion operation wherein a predetermined layer of rubber is removed from the outer surface of the blanket.

Thereafter, the rst composition is applied to the rubber Surface of the blanket, which results in slight swelling thereof. The blanket is then subjected to a final compressing and polishing operation to provide a layer of uniform thickness, having a smooth rubber surface. During the compressing operation the grain is reduced and a superior printing surface is provided.

In accordance with the present invention, apparatus for carrying out some of the method steps outlined above are provided. For example, the preliminary smoothing operation and the linal compressing and polishing operation may be carried out on a rolling mill 15, shown in FIG. 3. The mill may comprise a plurality of rollers suitably interconnected by means of a chain drive and to a motor source for actuation of the rollers simultaneously. Inthepresent instance three drive rollers 17,

18 and 19 are provided which are spaced apart and adapted to rotate in a counter-clockwise direction with respect toFIG. 3. -Each of the rollers (from left to. right -with reference to FIG. 3) may if desired be driven at a successively faster rate tor-effect a slipping action between the-rollers -18 and 19 and the blanket-which produces a slight amount of smoothing of the outer layers of the blanket. The-drive rollers 17, 18 and 19 -are provided with complementary co-acting idler rollersZtl, 21 and 22, respectively, which are spaced from the drive rollers to provide a small clearance therebetween. The drive rollers 17, 18 and 19 are spaced from their respective idler rollers 20, 21 and 22. to provide progressively smaller clearances from left to right asviewed'in FIG. 3; that is, the distance between the peripheral edges of the rollers 17 and 20 is slightly greater than the distance between the peripheral edges of the rollers 18 and 21, which in turn is greater than the peripheral spacing between rollers '19 and 22.

'In thismanner, as the blanket is passed through the mill pressing and polishing operation where the rubber surface Offthe blanket-is in contact with the drive rollers as the blanket passes through the mill, a hardening of the rubber layer is achieved by the contrast of heat and cold.

In accordance with the present invention, the reducing operationrnaysbe carried out on an abrasion .apparatus as' illustrated in FIGS. 4 and 5. The apparatuscomprises a supportstructure, anda main blanket roll 32, rotatably supported on'thesupport structure 30, which may be drivenby a motor 34connected to the main blanket roll32 by means of achain dr-ive36. An` idler roll 38 is rotatably. mounted in al support'39 which is movable lengthwise of the support structureti, so that the roll 33 may be. moved longitudinally with respect to the main blanket' roll 32. A-plurality of blankets may be connected end-to-end,'asY shown in FIG. 5,y byv means of tapes to form a continuous belt. vThe blankets are spaced-be- -tween the rolls 38 and'32, so that theirupper, or rubber,

layer faces outwardly, and are maintained taut there- .between by means of a pairLofV air-actuated tensioning mechanism 40 disposediadjacent outer ends of the roller '38. Each of'the tensioning mechanisms comprises a cylinder 41 .mounted at one end of .the support structure 30 and a piston '42 slidably. mounted in the cylinder- 41 and connected to the idler roll support-39. The pistons V42 are'actuatable lengthwisel of the support structure 30 to vregulate the position of the roller 38 with respect to the` roller 32. In this way the blankets may be secured end to end between the rollers 32 and 38 and the pistons 42 actuatedV to move' the idler roller 38 away Vfrom'the roller 32 toprovidea predetermined tension in the loop of blankets.

A cylinder 44 having abrasive means on its outer peripheral surface ispositioned adjacent the main blanket roll 32 andy rotated by means of a motor 45 connected to the roll, for example, by means of a chain drive 46. As shown in FIG. .4, the abrasion cylinder 44 is'rnounted on a support 47 movable lengthwise ofthe support structure '30 and may be rotated in a direction opposite to -that of the main blanket roll 32. Means are. provided vfor actuating the abrasion rollery 44 into engagement with the'endlessloop of blankets on the blanket roll 32. For

example, a pair of .fluid cylinders 48, 48 mounted on the support structure 30 and having their pistons 49, 49 connected to the support frame 47, maybeprovided to move `the frame 47 back and forth with respect to the blanket roll 32 as desired. The roller 44 may also be actuated axially of the blanket roller 32 by means of a lever arm 52 pivotally connectedto the frame 47 at 54 and at its outerends to the roller 44 and the'piston 55 of a iuid cylinder 56. Reciprocation of the pistonSS of the tluid eylinder'S effects. reciprocation of the roller 44' in .a direction axially of the main blanket roller 32. A reversing valve 57 is operativelyconnectedto the cylinder 56 to eifect reciprocating motion of the piston 55.

Means are provided to actuate the abrasion roller 44 lengthwise of the support structure 30 to engage the blankets on the roll 32 and remove a predeterminedflayer of rubber from their outer surface. vTo this end a pair of fluid cylinders 60, are supported on the frame-30 having their pistons-61, 61.connected to the abrasion roller support frame 47. A pair of adjustable stop members 62 are mounted on the support structure .30,as shown, which may be selectively positioned on the support structure 30 to engage with the abrasion rollersupport frame 47. When the desired amount has been removed from the outer surface of'the blankets, the rate of feed of the abrasion roller 44 may be selectively slowed down during the abrasion operation for greater precision by means of a check unit' 63 which transfers actuation of the roller 44 from the liuid cylinder 48 to thecylinders 60, 60 at a predetermined position.

In the operation of the apparatus described, the blankets are moved in a counter-clockwise direction with respect to'FIG. 5 about the main blanket roller 32, with-the outer surface thereof facing outwardly. The abrasion cylinder 44 which is oscillated axially of the blanket roller 32- by the` piston S5 of theffluid cylinder 56 ismoved toward the blanket roller 32 by means of the pistons.49. When the abrasion roller'44 has been moved .to a predetermined position, as determined by thecheck unit 63, actuation of the roller` 44 is transferred to the uid cylinders 60, whichmove the roller 44 at a slower rate-for the nish cut. The termination of the grinding-sequence is determined by engagement of the abrasionv roller support frame47 with the stop lmembers62.

ThisV is a division ofmy co-pending. application Serial Number 20,075, filed AprilS, 1960, and Vallowed June 18, 1962, now PatentNo. 3,075,247,:dated January 29, 1963.

While a particular -form of the present -invention'has been illustrated and described herein, it is lto be understood that changes and modifications may be incorporated therein within the scope of the following claims:

I claim:

1. Apparatus. for use in processing blanketsconsisting of a layer of resilient material .havingan'outer transverse surface and a cloth backing, comprising; a supportstructure, a blanket roll rotatably mountedsonsaid support structure, an idler roll -mounted onsaid support-structure spaced from said blanket roll, saidfblanket adapted t0 be moved in an endless path about said blanket roll and said Vidler roll, a hydraulic actuator normally urgingfsaid idler roll in a direction away from said blanket roll lthereby to maintain the blanket taut during movement in an endless path about said blanket and idler rolls and provide a substantially unform tension on the'blanket, a cylinder mounted in said support structure having abrasive means on the outer periphery thereof adapted to rotate about an axisV parallel to the axis of rotation of said blanket roll and aligned relative to said blanket roll to engage the blanket therebetween, means for effecting oscillatory movement of said abrasive cylinder along its rotational axis, rst hydraulic means for moving said cylinder at a predetermined rate toward said blanket roll in engagement with .said blanket to remove a predetermined amount of material from the outer surface thereof, second hydraulic means operable to move said cylinder at a rate slower than said predetermined rate to remove another predetermined amount of material from the outer surface thereof and a check unit operable to selectively effect transfer of actuation of said cylinder from said rst hydraulic means to said second hydraulic means.

2. Apparatus according to` claim l including adjustable stop means mounted on said support structure adapted to limit movement of said cylinder toward said blanket.

References Cited in the le of this patent UNITED STATES PATENTS Fowle Jan. 22, 1889 Carroll Oct. 26, 1915 Scrimgeour Jan. 22, 1935 Schulte Apr. 23, 1935 Dunigan Nov. 29, 1960 Eversole May 8, 1962 

1. APPARATUS FOR USE IN PROCESSING BLANKETS CONSISTING OF A LAYER OF RESILIENT MATERIAL HAVING AN OUTER TRANSVERSE SURFACE AND A CLOTH BACKING, COMPRISING; A SUPPORT STRUCTURE, A BLANKET ROLL ROTATABLY MOUNTED ON SAID SUPPORT STRUCTURE, AN IDLER ROLL MOUNTED ON SAID SUPPORT STRUCTURE SPACED FROM SAID BLANKET ROLL, SAID BLANKET ADAPTED TO BE MOVED IN AN ENDLESS PATH ABOUT SAID BLANKET ROLL AND SAID IDLER ROLL, A HYDRAULIC ACTUATOR NORMALLY URGING SAID IDLER ROLL IN A DIRECTION AWAY FROM SAID BLANKET ROLL THEREBY TO MAINTAIN THE BLANKET TAUT DURING MOVEMENT IN AN ENDLESS PATH ABOUT SAID BLANKET AND IDLER ROLLS AND PROVIDE A SUBSTANTIALLY UNFORM TENSION ON THE BLANKET, A CYLINDER MOUNTED IN SAID SUPPORT STRUCTURE HAVING ABRASIVE MEANS ON THE OUTER PERIPHERY THEREOF ADAPTED TO ROTATE ABOUT AN AXIS PARALLEL TO THE AXIS OF ROTATION OF SAID BLANKET ROLL AND ALIGNED RELATIVE TO SAID BLANKET ROLL TO ENGAGE THE BLANKET THEREBETWEEN, MEANS FOR EFFECTING OSCILLATORY MOVEMENT OF SAID ABRASIVE CYLINDER ALONG ITS ROTATIONAL AXIS, FIRST HYDRAULIC MEANS FOR MOVING SAID CYLINDER AT A PREDETERMINED RATE TOWARD SAID BLANKET ROLL IN ENGAGEMENT WITH SAID BLANKET TO REMOVE A PREDETERMINED AMOUNT OF MATERIAL FROM THE OUTER SURFACE THEREOF, SECOND HYDRAULIC MEANS OPERABLE TO MOVE SAID CYLINDER AT A RATE SLOWER THAN SAID PREDETERMINED RATE TO REMOVE ANOTHER PREDETERMINED AMOUNT OF MATERIAL FROM THE OUTER SURFACE THEREOF AND A CHECK UNIT OPERABLE TO SELECTIVELY EFFECT TRANSFER OF ACTUATION OF SAID CYLINDER FROM SAID FIRST HYDRAULIC MEANS TO SAID SECOND HYDRAULIC MEANS. 